High voltage DC current tripout device

Abstract

A current-breaking device for high-voltage direct current includes a main conduction-line and a secondary conduction-line connected in parallel between its terminals. The main conduction-line comprises a first controlled-switch and a circuit connected in series. The circuit comprises a first current-limiter and a first capacitor connected in parallel. The secondary conduction-line comprises a second controlled-switch. These conduction lines cooperate to form an oscillating circuit that oscillates with an amplitude that is at least equal to limiting current passing through the current limiter.

Having described the invention, and a preferred embodiment thereof, what is claimed as new, and secured by letters patent is: 
     
       1. An apparatus comprising a current-breaking device for high-voltage direct current, wherein said current-breaking device comprises first and second terminals, a main conduction-line, a secondary conduction-line, an oscillating circuit, and a control circuit, wherein said main conduction-line and said secondary conduction-line are connected in parallel between said first and second terminals, wherein said main conduction-line comprises a first controlled-switch and a circuit connected in series with said first controlled-switch, wherein said circuit comprises a first current-limiter and a first capacitor connected in parallel, wherein said current limiter is configured such that current passing through said current limiter is maintained at a level that is less than or equal to a limiting current, wherein said secondary conduction-line comprises a second controlled-switch, wherein said main conduction-line and said secondary conduction-line cooperate to form said oscillating circuit at said terminals of said first controlled-switch when said first and second controlled-switches are closed, wherein said oscillating circuit oscillates with an oscillation amplitude that is at least equal to said limiting current of said current limiter when said limiting current is passing through said current limiter circuit, wherein said control circuit operates in a first mode and in a second mode, wherein, in said first mode, said control circuit is configured to close said first controlled-switch closed and to open said second controlled-switch, and wherein, in said second mode, said control circuit is configured to open said first controlled-switch and to close said second controlled-switch. 
     
     
       2. The apparatus as claimed in  claim 1 , wherein said current limiter comprises a superconducting resistor. 
     
     
       3. The apparatus of  claim 1 , wherein said secondary conduction-line comprises a second capacitor connected in series with said second controlled-switch. 
     
     
       4. The apparatus of  claim 1 , wherein said oscillating circuit resonates at a resonant frequency that is less than or equal to five kilohertz. 
     
     
       5. The apparatus of  claim 1 , wherein, in operation, current drift in said oscillating circuit relative to time is no greater than five-hundred amperes per microsecond. 
     
     
       6. The apparatus of  claim 1 , wherein said oscillating circuit resonates at a resonant frequency that is no less than five-hundred Hertz. 
     
     
       7. The apparatus of  claim 1 , wherein said secondary conduction-line comprises an inductor connected in series with said second controlled-switch. 
     
     
       8. The apparatus of  claim 1 , wherein said control circuit is configured to detect an overcurrent in said first mode of operation. 
     
     
       9. The apparatus of  claim 1 , wherein said control circuit is configured to respond to detection of an overcurrent by generating an opening signal for said first controlled-switch, wherein a delay between detection of said overcurrent and generating said opening signal is at most fifty milliseconds. 
     
     
       10. The apparatus of  claim 1 , wherein, in said second mode of operation, said control circuit is configured to generate an opening signal for said first controlled-switch and to generate a closing signal for said second controlled-switch at least five-hundred microseconds after having generated said opening signal. 
     
     
       11. The apparatus of  claim 1 , further comprising an overvoltage arrestor, wherein said overvoltage arrestor and said second capacitor are connected in parallel. 
     
     
       12. The apparatus of  claim 1 , wherein said current-breaking device is dimensioned to apply a potential difference that is at least equal to ten kilovolts between said first and second terminals and to support a current that is at least equal to one kiloamp through said first and second terminals.